Description of the Prior Art
According to processes known until now, the reaction gases, which accumulate in a gas generator lined with brick after termination of the gasification reaction of coal or carbon containing materials, are fed to a waste heat system connected at the outlet side of a pressure vessel, saturated steam preferably being produced in the waste heat system. The pressure stage of this known waste heat system in the form of a water-tube or fire-tube boiler is generally between 40 and 120 bar. The gas produced in this way is utilized within a larger process or within several process cycles in which the gas generator and the waste heat system are frequently connected in series with a chemical plant in which the generated synthesis gas is further processed.
When using gasification reactors and waste heat systems in connection with steam generators, the live steam conditions produced by the waste heat system, however, are essentially greater than in the above mentioned known waste heat system. In this process it concerns a connection between a known steam turbine process and a gas turbine process, in which there is a special advantage in an essential increase of efficiency. If a gas generator with a waste heat system is integrated in such a combination process, there is, regarding the utilization of waste heat to generate steam, a requirement to produce high-pressure, superheated steam which can be supplied to the or several steam turbine(s) together with the steam generated in a steam generator block of conventional design. This may be effected in the intermediary or end stage. In the course of further development, the pressures and temperatures of the operating media are very considerably increased during generation of high-pressure and superheated steam in power plant processes. In order to obtain a high efficiency, the power plants are in most cases operated with live steam conditions of more than 530.degree. C. and pressures of more than 200 bar. The live steam generated in a waste heat system of a coal gasification plant therefore must have the same steam parameters in this combination process.